U.S. patent application number 10/836720 was filed with the patent office on 2006-04-06 for medical device initialization method & system.
Invention is credited to Richard Aparo, Adam Casey, Charles Cox, Calvert Hawkes, Luis Malave, Mohsen Moghaddami, Stuart Perry, Marc Vogt, Paul Wolejko, John V. Yannone.
Application Number | 20060074381 10/836720 |
Document ID | / |
Family ID | 33437066 |
Filed Date | 2006-04-06 |
United States Patent
Application |
20060074381 |
Kind Code |
A1 |
Malave; Luis ; et
al. |
April 6, 2006 |
Medical device initialization method & system
Abstract
A system includes a remote controller and an infusion pump. The
infusion pump includes an RF telemetry portion configured to
receive an RF data signal from the remote controller. A processing
portion is configured to process the RF data signal received by the
RF telemetry portion. A dispensing apparatus, responsive to the
processing portion of the medical device, dispenses medicament in
accordance with the RF data signal. The dispensing apparatus
includes a fill sensor for providing an initialization signal to
the processing portion of the medical device upon the dispensing
apparatus being filled with at least a defined volume of
medicament.
Inventors: |
Malave; Luis; (Waltham,
MA) ; Moghaddami; Mohsen; (Londonderry, NH) ;
Vogt; Marc; (Rye, NH) ; Wolejko; Paul;
(Newburyport, MA) ; Yannone; John V.; (Seabrook,
NH) ; Casey; Adam; (Abington, MA) ; Aparo;
Richard; (West Newton, MA) ; Cox; Charles;
(Cambridge, MA) ; Perry; Stuart; (Wellesley Hills,
MA) ; Hawkes; Calvert; (Sarasota, FL) |
Correspondence
Address: |
INSULET CORPORATION
9 Oak Park Drive
Bedford
MA
01730
US
|
Family ID: |
33437066 |
Appl. No.: |
10/836720 |
Filed: |
April 30, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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60466708 |
Apr 30, 2003 |
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60466704 |
Apr 30, 2003 |
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60466589 |
Apr 30, 2003 |
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Current U.S.
Class: |
604/93.01 |
Current CPC
Class: |
A61M 5/14248 20130101;
A61M 2205/3569 20130101; A61M 2205/3592 20130101; A61M 2209/01
20130101; G16H 10/65 20180101; G16H 40/63 20180101; A61M 2205/60
20130101; G16H 20/17 20180101 |
Class at
Publication: |
604/093.01 |
International
Class: |
A61M 31/00 20060101
A61M031/00 |
Claims
1. A system for delivering a fluid to a patient comprising: a
remote controller; and an infusion pump including: an RF telemetry
portion configured to receive an RF data signal from the remote
controller; a processing portion configured to process the RF data
signal received by the RF telemetry portion; and a dispensing
apparatus, responsive to the processing portion of the medical
device, for dispensing medicament in accordance with the RF data
signal; wherein the dispensing apparatus includes a fill sensor for
providing an initialization signal to the processing portion of the
medical device upon the dispensing apparatus being filled with at
least a defined volume of medicament.
2. The system of claim 1 wherein the defined volume of medicament
is fifty units.
3. The system of claim 1 wherein the medicament is insulin.
4. The system of claim 1 wherein the dispensing apparatus includes
a fluid reservoir and the fill sensor is a normally open mechanical
switch that closes upon the reservoir being filled with the at
least a defined volume of medicament.
5. A medical device comprising: an RF telemetry portion configured
to receive an RF data signal; a processing portion configured to
process the RF data signal received by the RF telemetry portion;
and a dispensing apparatus, responsive to the processing portion of
the medical device, for dispensing medicament in accordance with
the RF data signal; wherein the dispensing apparatus includes a
fill sensor for providing an initialization signal to the
processing portion of the medical device upon a fluid reservoir of
the dispensing apparatus being filled with at least a defined
volume of medicament.
6. The medical device of claim 5 wherein the defined volume of
medicament is about one half of the reservoir volume.
7. The medical device of claim 5 wherein the medicament is
insulin.
8. The medical device of claim 5 wherein the fill sensor is a
normally-open mechanical switch that closes upon the fluid
reservoir being filled with the at least a defined volume of
medicament.
9. The medical device of claim 5 wherein, upon receipt of the
initialization signal by the processing portion, the RF telemetry
portion periodically polls a defined RF frequency to determine if
the RF data signal is available for receipt.
10-12. (canceled)
13. The medical device of claim 5 wherein the RF telemetry portion
includes compact antenna.
14. The medical device of claim 13 wherein the compact antenna is a
spirally-wound antenna.
15. The medical device of claim 13 wherein the compact antenna is a
helically-wound antenna.
16. The medical device of claim 13 wherein an effective length of
the compact antenna is a defined percentage of a wavelength of a
carrier signal.
17. The medical device of claim 5 wherein the processing portion
includes: a main processing unit; and an interlock processing
unit.
18. The medical device of claim 5 wherein the RF data signal
includes a defined validation sequence and the RE telemetry portion
is further configured to: examine the RF data signal to confirm
that the RF data signal includes the defined validation
sequence.
19. The medical device of claim 18 wherein the RF telemetry portion
is further configured to: transmit an acknowledgement signal to the
device transmitting the RF data signal if it is determined that the
RF data signal includes the defined validation sequence.
20. The medical device of claim 5 wherein the RF telemetry portion
and at least a first portion of the processing portion are
incorporated into a single microchip.
21. The medical device of claim 20 wherein the single microchip is
an application-specific integrated circuit.
22. A method of extending the shelf life of a medical device
comprising: placing the medical device into a low-power sleep mode,
wherein the medical device includes a processing portion and a
dispensing apparatus; filing the dispensing apparatus with at least
a defined volume of medicament; and providing an initialization
signal to the processing portion of the medical device.
23. The method of claim 22 wherein the medical device includes an
RF telemetry portion, the method further comprising: periodically
polling a defined RF frequency, via the RF telemetry portion, to
determine if an RF data signal is available for receipt.
24. (canceled)
25. The method of claim 23 wherein the RF data signal is available
for receipt and the RF data signal includes a defined validation
sequence, the method further comprising: examining the RF data
signal to confirm that the RF data signal includes the defined
validation sequence.
26. The method of claim 25 further comprising: transmitting an
acknowledgement signal to the device transmitting the RF data
signal if it is determined that the RF data signal includes the
defined validation sequence.
Description
RELATED APPLICATIONS
[0001] This application claims the priority of the following
applications, each of which is herein incorporated by reference:
U.S. Provisional Application Ser. No. 60/466,708, entitled
"Infusion Device System Hardware and Method of Using The Same",
filed 30 Apr. 2003; U.S. Provisional Application Ser. No.
60/466,704, entitled "Infusion Device System Programming and Method
of Operating an Infusion Device", filed 30 Apr. 2003; and U.S.
Provisional Application Ser. No. 60/466,589, entitled "Remote
Communications Methods for Infusion Devices", and filed 30 Apr.
2003.
FIELD OF THE INVENTION
[0002] This invention relates to medical devices/systems and, more
particularly, to medical devices/system having RF communication
capabilities.
BACKGROUND
[0003] Ambulatory infusion devices/pumps were developed to deliver
liquid medicaments to patients. Typically, infusion devices are
capable of providing sophisticated fluid delivery profiles (e.g.,
bolus doses, continuous basal infusions, variable flow delivery
rates, etc.) and often automate the delivery of insulin when
treating diabetes.
[0004] Currently available ambulatory infusion devices are
typically bulky, heavy, expensive and fragile. Additionally, these
devices are typically difficult to program and prepare for
infusion. Further, filling these devices with the medicament can be
difficult and often requires that the user carry both the
medicament and the filling accessories. Often, these devices
require specialized care, maintenance, and cleaning to assure
proper functionality and safety for their intended long term use.
Unfortunately, as these devices tend to be expensive, healthcare
providers typically limit the patient populations to which these
devices are made available.
SUMMARY OF THE INVENTION
[0005] According to an aspect of this invention, a system for
delivering a fluid to a patient includes a remote controller and an
infusion pump. The infusion pump includes an RF telemetry portion
configured to receive an RF data signal from the remote controller.
A processing portion is configured to process the RF data signal
received by the RF telemetry portion. A dispensing apparatus,
responsive to the processing portion of the medical device,
dispenses medicament in accordance with the RF data signal. The
dispensing apparatus includes a fill sensor for providing an
initialization signal to the processing portion of the medical
device upon the dispensing apparatus being filled with at least a
defined volume of medicament.
[0006] One or more of the following features may also be included.
The defined volume of medicament (e.g., insulin) may be fifty
units. The dispensing apparatus may include a fluid reservoir and
the fill sensor may be a normally-open mechanical switch that
closes upon the reservoir being filled with the at least a defined
volume of medicament.
[0007] According to another aspect of this invention, a medical
device includes an RF telemetry portion configured to receive an RF
data signal. A processing portion is configured to process the RF
data signal received by the RF telemetry portion, and a dispensing
apparatus, responsive to the processing portion of the medical
device, dispenses medicament in accordance with the RF data signal.
The dispensing apparatus includes a fill sensor for providing an
initialization signal to the processing portion of the medical
device upon a fluid reservoir of the dispensing apparatus being
filled with at least a defined volume of medicament.
[0008] One or more of the following features may also be included.
The defined volume of medicament (e.g., insulin) may be about one
half of the volume of the fluid reservoir. The fill sensor may be a
normally-open mechanical switch that closes upon the fluid
reservoir being filled with the at least a defined volume of
medicament.
[0009] Upon receipt of the initialization signal by the processing
portion, the RF telemetry portion may periodically poll a defined
RF frequency to determine if the RF data signal is available for
receipt. The defined RF frequency may be within a frequency band of
13.40-13.70 megahertz. The RF telemetry portion may be configured
to receive data encoded within a 13.56 megahertz carrier signal
and/or transmit data encoded within a 13.56 megahertz carrier
signal.
[0010] The RF telemetry portion may include a compact antenna
(e.g., a spirally-wound or helically-wound antenna). The effective
length of the compact antenna may be a defined percentage of a
wavelength of a carrier signal.
[0011] The processing portion may include a main processing unit,
and an interlock processing unit. The RF data signal may include a
defined validation sequence and the RF telemetry portion may be
configured to examine the RF data signal to confirm that the RF
data signal includes the defined validation sequence. The RF
telemetry portion may be configured to transmit an acknowledgement
signal to the device transmitting the RF data signal if it is
determined that the RF data signal includes the defined validation
sequence. The RF telemetry portion and at least a first portion of
the processing portion are incorporated into a single microchip
(e.g., an application-specific integrated circuit).
[0012] According to another aspect of this invention, a method of
extending the shelf life of a medical device includes placing the
medical device into a low-power sleep mode. The medical device
includes a processing portion and a dispensing apparatus. The
dispensing apparatus is filled with at least a defined volume of a
medicament, and an initialization signal is provided to the
processing portion of the medical device.
[0013] One or more of the following features may also be included.
The medical device may include an RF telemetry portion. The RF
telemetry portion may periodically poll a defined RF frequency to
determine if an RF data signal is available for receipt. The
defined RF frequency may be within a frequency band of 13.40-13.70
megahertz.
[0014] If the RF data signal is available for receipt, the RF data
signal may be examined to confirm that the RF data signal includes
a defined validation sequence. An acknowledgement signal may be
transmitted to the device transmitting the RF data signal if it is
determined that the RF data signal includes the defined validation
sequence.
[0015] The details of one or more implementations are set forth in
the accompanying drawings and the description below. Other features
and advantages will become apparent from the description, the
drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a diagrammatic perspective view of a fluid
delivery system, including an infusion pump and a remote
controller;
[0017] FIG. 2 is an isometric top view of the infusion pump of FIG.
1;
[0018] FIG. 3 is an isometric bottom view of the infusion pump of
FIG. 1;
[0019] FIG. 4 is an isometric view of the infusion pump of FIG. 1
(with the upper housing removed); and
[0020] FIG. 5 is a front view of the remote controller of FIG. 1;
and
[0021] FIG. 6 is a diagrammatic view of the infusion pump of FIG.
1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Referring to FIGS. 1-4, there is shown a
remotely-controlled, disposable infusion pump 10, which is
typically used with remote controller 100 (shown in FIGS. 1 and 5).
Examples of similar infusion pumps are disclosed in co-pending U.S.
patent application Ser. No. 09/943,992, filed on Aug. 31, 2001,
which is herein incorporated by reference. Infusion pump 10 may
incorporate a new and improved RF telemetry processor and local
processor, which are discussed below in greater detail and shown in
FIG. 6.
[0023] While the new and improved RF telemetry processor and local
processor of the present disclosure are described with reference
the exemplary embodiment of infusion pump 10 and remote controller
100, it should be understood that the present disclosure is broadly
applicable to any form of programmable infusion pumps. For example,
the new and improved RF telemetry processor and local processor of
the present disclosure may be used with programmable ambulatory
insulin infusion pumps of the sort currently commercially available
from a number of manufacturers, including without limitation and by
way of example, Medtronic Minimed under the trademark PARADIGM,
Animas Corporation under the trademarks IR 1000 and IR 1200, Smiths
Medical under the trademark Deltec COZMO, DANA Diabecare USA, and
others.
[0024] Infusion pump 10 is used to deliver mendicants to a person
or animal. The types of mendicants that may be delivered (via
infusion pump 10) include, but are not limited to, insulin,
antibiotics, nutritional fluids, total parenteral nutrition (i.e.,
TPN), analgesics, morphine, hormones/hormonal drugs, gene therapy
drugs, anticoagulants, analgesics, cardiovascular medications, AZT,
or chemotherapeutics, for example. The types of medical conditions
that infusion pump 10 may be used to treat include, but are not
limited to, diabetes, cardiovascular disease, temporal pain,
chronic pain, cancer, AIDS, neurological disease, Alzheimer's
Disease, ALS, Hepatitis, Parkinson's Disease or spasticity, for
example.
[0025] Infusion pump 10 is typically disposable and adapted for
attachment to the skin of a patient for infusing a mendicant, such
as insulin, into the patient on a regular basis. The infusion pump
10 may have a usable life of about 72 hours, for example, before
being removed from the patient and discarded.
[0026] Referring to FIG. 4, infusion pump 10 typically includes a
dispenser assembly 12 for causing mendicant from fluid reservoir 14
to flow through flow path assembly 16 to transcutaneous access tool
(e.g., needle) 18 for infusion into the patient. The volume of
reservoir 14 is chosen to best suit the therapeutic application of
infusion pump 10, impacted by such factors as the available
concentrations of mendicant to be delivered, the acceptable time
between refill/disposal of infusion pump 10, and size constraints,
for example
[0027] Local processor 20 (e.g., one or more processors or
electronic microcontrollers) is connected to dispenser assembly 12,
and is programmed to control the flow of mendicant to the
transcutaneous access tool 18 based on flow instructions from the
separate, remote controller 100 (as shown in FIG. 5). RF telemetry
processor 22, which is coupled to local processor 20, receives flow
instructions from remote controller 100 and provides them to local
processor 20.
[0028] Infusion pump 10 typically includes a power supply (e.g., a
battery or capacitor; not shown) that supplies power to local
processor 20. This power supply may be non-serviceable (e.g., a
litium ion battery soldered to a circuit board) or replaceable
(e.g., a AAA battery).
[0029] As shown in FIG. 4, infusion pump 10 may also include
various sensors/transducers, such as a flow condition sensor
assembly (not shown) or a fill sensor 24 (to be discussed below in
greater detail), that transmit information to local processor 20
concerning the condition and status of infusion pump 10.
[0030] Infusion pump 10 includes housing 26, which contains and
protects dispenser assembly 12, reservoir 14, flow path assembly
16, transcutaneous access tool 18, local processor 20, and RF
telemetry processor 22. Infusion pump 10 may be provided with an
adhesive layer 28 (as shown in FIG. 3) on the lower surface 30 of
housing 26 for temporarily securing infusion pump 10 directly to
the skin of the patient.
[0031] As discussed above, infusion pump 10 includes RF telemetry
processor 22 that facilitates the programming of local processor 20
via remote controller 100. Commands may be transmitted between
infusion pump 10 and remote controller 100 via a communication
circuit (not shown) incorporated into remote controller 100.
[0032] The outer surfaces of housing 26 are typically free of any
user input components (e.g., buttons/interfaces/electromechanical
switches) that would allow the user to program local processor 20),
thus reducing the size, complexity and cost of infusion pump 10.
Alternatively, infusion pump 10 may include an integrated user
interface (not shown) with some or all of the features of remote
controller 100, thus allowing the user to directly input
instructions/commands to infusion pump 10.
[0033] Remote controller 100 typically includes: user input
components that allow the user to provide information; user output
components that allow the user to receive information; a processor
(hereinafter referred to as the "remote" processor) coupled to the
user input components and the user output components and configured
to provide instructions to the infusion pump; and one or more
computer programs that provide instructions to the remote
processor.
[0034] The computer programs instruct the remote processor to
receive information from the user via the user input components,
provide information to the user via the user output components, and
provide instructions/commands to infusion pump 10.
[0035] As shown in FIG. 5, the user input components may include:
electromechanical switches, such as three soft key selection
switches 102, 104, 106; an up/down navigation toggle switch 108; a
"display user information" switch 110; a power on/off switch 112; a
"check pump status" switch 114; and an "instant bolus" switch 116.
The user output components may include: a visual display (e.g., LCD
screen 118); a sound making device (e.g., a buzzer; not shown);
and/or a vibrating element (not shown).
[0036] Soft key selection switches 102, 104, 106 cause remote
controller 100 to perform the action indicated by the label (on LCD
screen 118) above the switch in question. If there is no label
above one of the switches 102, 104, 106, pressing the switch at
that time will result in no activity. The up/down navigation toggle
switch 108 is used to navigate a menu, enter a number, or change a
character during text entry.
[0037] LCD screen 118 displays icons to distinguish between various
features. For non-menu pages, the icon may be displayed in the
upper-left corner of LCD screen 118. On menu pages, the icon may be
displayed to the left of the currently highlighted menu item,
except on the main menu where an icon is displayed to the left of
all menu items.
[0038] System functions are navigated via menus, which list the
functions available to the user and allow the user to quickly
enable the appropriate function. These menus consist of a set of
options in a list, with a highlight that moves up and down in
response to the up/down navigation toggle switch 108. When the
highlight is over the appropriate option, the user depresses one of
the three soft key selection switches 102, 104, 106 to select the
option. Text entry in the system is accomplished via the soft keys
102, 104, 106 and the up/down toggle switch 108. The user moves the
flashing up/down icon left and right using two of the soft keys,
and changes the character above the icon using the up/down
navigation toggle switch 108. Pressing the up/down toggle switch
108 changes the letter to the next letter in the sequence.
[0039] Although not shown, remote controller 100 may include
additional components such as an integrated glucose meter (e.g., a
TheraSense.RTM. FreeStyle.TM. Glucose Meter that is available from
Abbott Diabetes Care of Alameda, Calif.). If such additional
components are includes, the user interface components of remote
controller 100 are typically configured to operate the additional
components.
[0040] According to one embodiment, RF telemetry processor 22 of
infusion pump 10 receives electronic communication from remote
controller 100 using radio frequency or other wireless
communication standards/protocols. In a preferred embodiment, RF
telemetry processor 22 is a bidirectional communication device,
that includes a receiver portion and a transmitter portion. This,
in turn, allows infusion pump 10 to transmit information to remote
controller 100. In this embodiment, remote controller 100 is also
capable of bidirectional communication, thus allowing remote
controller 100 to receive the information sent by infusion pump
10.
[0041] Local processor 20 of infusion pump 10 typically includes
all of the computer programs and electronic circuitry needed to
allow a user to program local processor 20. Such circuitry may
include one or more microprocessors, digital and/or analog
integrated circuits, and other various passive and active
electronic components, for example.
[0042] As will be discussed below in greater detail, local
processor 20 also typically includes the programming, electronic
circuitry and memory to activate dispenser assembly 12 at the
programmed time intervals. In a preferred embodiment, user
instructions/commands are processed in remote controller 100 to
generate one or more specific flow control instructions, (i.e.,
drive signals) for infusion pump 10. Alternatively, the user may
input the instructions/commands into remote controller 100, such
that the instructions/commands are transmitted from remote
controller 100 to infusion pump 10, where the instructions/commands
are processed to generate the flow control instructions (i.e.,
drive signals) for infusion pump 10.
[0043] Referring to FIG. 6, local processor 20 typically includes
main processing unit 150 and interlock processing unit 152.
Additionally, infusion pump 10 typically also includes main alarm
unit 154, interlock alarm unit 156, RF telemetry processing unit 22
(which includes RF (i.e., radio frequency) portion 158 and a
pass-through portion 160).
[0044] In order to conserve battery power, several of the
components of infusion pump 10 are maintained in a "sleep" mode
that reduces power consumption. RF portion 158 of RF telemetry
processing unit 22 "wakes up" at predefined intervals (e.g., every
125 milliseconds) and polls a defined frequency (e.g., 13.56
megahertz) to determine if remote controller 100 is trying to
communicate with infusion pump 10. If data packets are not
available for receipt, RF portion 158 of the RF telemetry
processing unit 22 returns to "sleep" mode for the predefined
interval.
[0045] However, if a data packet is available for receipt, RF
portion 158 receives the data packet and examines it to verify that
the packet was received from an authorized source. Typically, this
verification is performed by examining the content of the data
packet received to see if it contains a defined bit
signature/validation sequence (e.g., 0110 0110, or 1001 1001). If
present, RF portion 158 transmits an acknowledgement signal to
remote controller 100 that requests transmission of the instruction
set. Additionally, RF portion 158 may verify that the data packet
received is valid, which may be determined using, for example, a
checksum.
[0046] At this point, RF portion 158 "wakes up" main processing
unit 150 and the data packets received are provided to main
processing unit 150 for further examination and processing.
Typically, "wake up" signals are transmitted between communicating
devices (e.g., main processing unit 150, interlock processing unit
152, and RF telemetry processing unit 22, for example) via the
various buses (not shown) that interconnect the communicating
devices.
[0047] Main processing unit 150 may reexamine the received data
packet(s) to verify that infusion pump 10 is truly the intended
recipient of the data packet. As discussed above, one or more of
the data packets received typically includes a unique bit
signature/validation sequence that identifies the intended
recipient of the data packet. If the unique bit
signature/validation sequence within the packet does not match the
unique bit signature/validation sequence of infusion pump 10,
infusion pump 10 is not the intended recipient, the data packet is
rejected by main processing unit 150, and the main processing unit
150 notifies the RF portion 158 of the RF telemetry processing unit
22 that the data packet received was misdirected.
[0048] However, if infusion pump 10 is indeed the intended
recipient of the data packet, main processing unit 150 accepts the
data packet, as the received data packet is a portion of a valid
instruction set being transmitted by remote controller 100. This
packet receipt and examination process continues for
subsequently-received data packets until the instruction set
received is complete. Once received, the complete instruction set
includes a main instruction portion (for the main processing unit
150) and an interlock instruction portion (for the interlock
processing unit 152).
[0049] Once a complete instruction set is received, main processing
unit 150 wakes up interlock processing unit 152 so that the
interlock portion of the received instruction set can be
transferred to interlock processing unit 152. Typically, each data
packet received includes an interlock portion and a main portion
(in addition to the identification information described above).
The interlock portion (for use by interlock processing unit 152)
typically includes instructions in terms of pulses of medicament
(e.g., insulin) per unit time (e.g., per half hour). The main
portion (for use by main processing unit 150) typically includes
instructions in terms of the number of partial pulses of medicament
(e.g., insulin), and the delay between each partial pulse.
[0050] As stated above, RF telemetry processing unit 22 includes
pass-through portion 160 that allows for pass-through
communications between main processing unit 150 and interlock
processing unit 152, and between interlock processing unit 152 and
interlock alarm unit 156. As will be discussed below, pass-through
portion 160 of RF telemetry processing unit 22 acts as a conduit
that completes a circuit between the communicating devices, in that
RF portion 158 of RF telemetry processing unit 22 is isolated from
and does not modify the signals passed between the communicating
devices.
[0051] Additionally, pass-through portion 160 of RF telemetry
processing unit 22 includes status registers 162, 164 that are
readable and writable by devices external to RF telemetry
processing unit 22. As will be discussed below, status registers
162, 164 included in RF telemetry processing unit 22 allow main and
interlock processing units 150, 152 to confirm the operation of
dispenser assembly 12 and, in the event of a failure, prevent the
pump drive signals from reaching dispenser assembly 12.
[0052] As stated above, once a complete instruction set is
received, the interlock portion of the instruction set is
transferred to interlock processing unit 152. In the event that
interlock processing unit 152 does not acknowledge receipt of the
interlock portion of the instruction set, main processing unit 150
assumes that interlock processing unit 152 is malfunctioning and
initiates an alarm on main alarm unit 154.
[0053] Interlock processing unit 152 and main processing unit 150
are typically powered by separate power supplies (e.g., batteries
or capacitors; not shown), are synchronized using a common clock
(not shown), and each independently execute their received
instruction sets, resulting in a level of redundancy.
[0054] Often, a received instruction set will specify that a
defined dose of medicament be dispensed at predefined intervals
(e.g., ten minutes). At the expiration of one of these predefined
intervals, main processing unit 150 contacts (via pass-through
portion 160 of RF telemetry processing unit 22) interlock
processing unit 152 to confirm that it is the proper time for
dispensing the defined dose of medicament. If interlock processing
unit 152 fails to respond, main processing unit 150 assumes that
interlock processing unit 152 is malfunctioning and initiates an
alarm on main alarm unit 154.
[0055] Further, in the event that interlock processing unit 152
does not agree that it is the proper time to dispense the defined
dose of medicament, interlock processing unit 152 may initiate an
alarm on interlock alarm unit 156, via pass-through portion 160 of
RF telemetry processing unit 22. Additionally and/or alternatively,
main processing unit 150 may initiate an alarm on main alarm unit
154.
[0056] If both interlock processing unit 152 and main processing
unit 150 concur that it is time to dispense the defined dose of
medicament, main processing unit 150 provides the appropriate "pump
drive signal" to dispenser assembly 12.
[0057] After dispenser assembly 12 completes dispensing the
medicament, a completion signal is provided by dispenser assembly
12 to status register 162 to confirm that the medicament was
successfully dispensed. Main processing unit 150 and interlock
processing unit 152 monitor status register 162 to determine if the
medicament was dispensed. If, after a defined period of time (e.g.,
1-5 seconds), status register 162 fails to indicate that the
medicament was dispensed, main processing unit 150 assumes that
dispenser assembly 12 is malfunctioning and main processing unit
150 typically initiates an alarm on main alarm unit 154.
Additionally and/or alternatively, interlock processing unit 152
may initiate an alarm on interlock alarm unit 156 (via pass-through
portion 160 of RF telemetry processing unit 22).
[0058] In addition to the alarms, in the event that dispenser
assembly 12 fails to dispense the medicament, the main and/or
interlock processing units 150, 152 may provide a dispenser failure
signal to a second status register 164. The value of register 164
determines whether a relay 166 (e.g., a FET transistor) that is in
the signal line 168 that provides the "pump drive signal" to
dispenser assembly 12 is energized. Accordingly, in the event that
the dispenser assembly 12 fails to dispense the defined medicament
dose, dispenser assembly 12 is electrically disconnected from the
signal line 168 controlling dispenser assembly 12.
[0059] When RF telemetry processing unit 22 and remote controller
100 communicate by transmitting an RF data signal across wireless
communication channel 170, this communication typically occurs
across a non-restricted frequency band, which is a frequency band
that is dedicated to public use and not restricted for use by only
a certain class of devices. For example, a restricted frequency
band is 408-412 megahertz, which is reserved in the United States
for the exclusive use of medical devices. An example of a
non-restricted frequency band is 13.40-13.70 megahertz, which is
dedicated for public use worldwide and has no use device-class
restrictions. Specifically, RF telemetry processing unit 22 and
remote controller 100 typically communicate using a 13.56 megahertz
carrier signal, onto which the individual data packets within the
instruction set are encoded.
[0060] RF telemetry processing unit 22 is electrically coupled to
antenna assembly 172, which facilitates wireless communication with
remote controller 100. As it is desirable to minimize the size of
infusion pump 10, antenna 172 is typically a compact antenna design
(e.g., a spirally-wound antenna or a helically-wound antenna). As
is known in the art, it is desirable for the effective length of
antenna 172 to be a defined percentage (e.g., 25%, 50% or 100%) of
the wavelength of the carrier signal. For a carrier signal of 13.56
megahertz, the wavelength of the carrier signal is 22.100 meters
and, therefore, the defined percentages are 5.525 meters, 11.050
meters, and 22.100 meters, respectively.
[0061] Since it is desirable to reduce the physical size of
infusion pump 10, main processing unit 150 and RF telemetry
processing unit 22 are typically incorporated into a single
microchip 174, such as an ASIC (i.e., application specific
integrated circuit). If main processing unit 150 and RF telemetry
processing unit 22 are incorporated into a single microchip, two
separate power supplies (not shown) may be required to power the
microchip, a first power supply for main processing unit 150 and a
second power supply for RF telemetry processing unit 22.
Alternatively or additionally, it may be desirable to incorporate
interlock processing unit 152, RF telemetry processing unit 22, and
main processing unit 150 into a single microchip 174' (shown in
phantom). Since, by design, main processing unit 150 and interlock
processing unit 152 are powered by separate power supplies, if all
three processing units 150, 152, 22 are incorporated into a single
microchip, three power supplies may be required to power microchip
174'.
[0062] When incorporating two of more processing units (e.g., main
processing unit 150, interlock processing unit 152, and/or RF
telemetry processing unit 22) within a single microchip 174, it may
be desirable to locate antenna 172 outside of microchip 174, thus
reducing the risk of electromagnetic interference within microchip
174. Further, if RF telemetry processing unit 22 includes a boost
circuit 176 (i.e., to boost the amplitude of the signal broadcast
or received by antenna 172), it may be desirable to also locate
boost circuit 176 external to microchip 174 in order to shield main
processing unit 150 and/or interlock processing unit 152 from
electromagnetic interference.
[0063] Dispenser assembly 12 typically includes a fill sensor 24
(e.g., a normally open mechanical switch) that provide an
initialization signal to local processor 20 (i.e., main processing
unit 150 and/or interlock processing unit 152). As stated above,
dispenser assembly 12 includes a fluid reservoir 14 having a
plunger (not shown) that moves axially, such that the direction of
movement of the plunger is dependant upon whether the fluid
reservoir 14 is being filled or emptied. Prior to use of infusion
pump 10, fluid reservoir 14 must be filled with medicament, as it
is typically shipped from the factory empty.
[0064] Prior to filling fluid reservoir 14 of dispenser assembly 12
with medicament, infusion pump 10 is in an inactive state, thereby
reducing power consumption and lengthening shelf life. When it is
time to use infusion pump 10, the patient must fill the fluid
reservoir 14 of dispenser assembly 12 with medicament. Once fluid
reservoir 14 is filled with at least a predefined volume of
medicament (e.g., 50 units), the plunger of the fluid reservoir 14
contacts fill sensor 24, thereby providing the initialization
signal to local processor 20. At this point, the various components
of infusion pump 10 are initialized and begin to operate as
described above.
[0065] A number of implementations have been described.
Nevertheless, it will be understood that various modifications may
be made. Accordingly, other implementations are within the scope of
the following claims.
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